Surface treating apparatus



May 12, 1953 L. H. BISHOP ETAL SURFACE TREATING APPARATUS Filed Sept. 1, 1949 8110 WOW 'JOHN S- Fl/V/V ATTORNEY.

Patented May 12, 1953 UNITED STATES PATENT OFFICE SURFA E TREATING AHAR T S "Lewis H. Bishop and John S Finn, Burlingame, Califi, assignors, by mesne' assignments, to William H. Mead, Oakland, Calif.

Application September 1, lfldflrfierial N 0. 113,524

This invention relates to a surface treating apparatus and more particularly to apparatus which maybe used to abrade a path, such as a margin along the edges of sheet metel preparatory to welding, soldering or otherwise securing said edges together.

One important use .of the invention is the cleaning of metal sheets preparatory to welding, soldering, or otherwise iastening together the edges of cans, drums, tubing and other cylindrical objects, but the invention is not limited to such use. It may be used wherever edges of sheet materials are to be cleaned, whether on one side or on both sides, or wherever a margin or other path is to be thoroughly cleaned from rust, grease, paint and other foreign matter.

Edge cleaning, whether in preparation for weld seaming or for any other purpose, has heretoi'ore been a difficult, time-consuming operation. The cleaning must be perfect, for foreign matter will repel solder, and spoil Welds, andthereby cause imperfect seams so that the container or pipe will leak. Moreover it often becomes necessary to clean the margin of a- -metal sheet having a lithographic print, or other painted matter on its surface, and care must -be taken to clean the margin perfectly without injuring the paint.

Another important problem in quantity manufacture of scam welded tubular articles :has been how to obtain an edge-cleaning apparatus which can perform the desired operation at a sufficiently rapid rate of speed to keep up with the other machinery in a production line. Moreover the rapidity must be achieved without any sacrifice in accuracy. .Also it is desirable to achieve automatic operation in a production iline.

The present invention solves these problems and enables rapid automatic cleaning of hedge margins along one or both sidesof sheet material, as well as other paths. It does this :by pro- Viding a novel apparatus operating according to the method of the William Mead Patent ;No. 2,455,514., issued December 57,1948. The general method and apparatus described in the aforesaid patent include means to impel abrasive against a surface in an air blast and to withdraw spent abrasive by a suction current which is more "ntense than the impelling air blast. The t p 1;.- ing head may include an lair-permeablegabrasive-confining maze, ,so that .a stream vof air drawn into the head by thesuctionculirerit rail-1d impinges with the air blast stream inside .the e to carry away the spentabrasive.

In the present invention the operating head is -13 Claims. 01. 51-44;)

2 known an edge blasting box. It includes a housing having a slit therethrough; a pair of blast nozzles positioned on opposite sides of the she t, .50 as to project abrasive against the edge o 111.18 sheet, which is passed between the 1102-. ales and a suction opening where the spent abrasive is withdrawn. An air-permeable abrasire: fining maze fills the slit, keeping the abrasive inside the box and permitting the entry of an air stream which subsequently passes into the suction current. The maze is made in two sections, and the sheet material whose edge is being blasted is fed in and out of .the box between these two sections. The housing may also be provided with guide means to position the sheet being treated. Moreover, the box may be combined with automatic propelling means for .Continuously treating the sheet material.

Other objects and advantages of the invention will appear from the following description of a preferred embodiment. The description is illustrative .and is not intended as a narrow limitation of the invention. The scope of the invention will be apparent from the claims.

In the drawings:

Big. 1 is a view in elevation and partly in section or an apparatus embodying the principles of the invention. Two edge-blasting boxes are shown mounted at each side of a conveyor table, and the sheet material whose edges are to be cleaned is moved along the table. Each box is hinged so that it may be swung open, and its 998.1 position and the then position of its associated conduits are shown in dotted lines.

Big, 2 is a view in elevation and in section of 9116 of $1 .8 edge-blasting boxes taken along the line 2+2 o Fig. ,3 is a view in section along the line 3-4 ofFig. 2 and f Rig. 4 is a side elevation of a portion of a box Of .Fig. 1 with the maze-like member removed the e rom- ,Eig. 1 shows v,avframe it which supports a conveyor table ll. A. pair of continuous chains I2 and 1.3 may be moved across the table it by a motor (not shown) so as to propel sheet material 1L5 @lQI the table l i. A guide rail i l may be secured t0 the edge of the table it to keep the sheets E5 in line. In their course across the table l,l theedges it and l? of the sheets 5 pass through two edge-blasting boxes 20, where a? margin it along each of the two side edges 16 and I3 iscleaned preparatory to weld- Each box 20 includes two housing sections; an

upper housing section 2| and lower housing section 22. The lower housing section 22 may be secured rigidly to a pair of brackets 23, which in turn may be rigidly secured to the frame II) by wing nuts 24. A similar pair of brackets 25 may be secured to the upper housing section 2|. The brackets 25 are preferably mounted pivotally at 26 to the lower brackets 23, either directly or through adjustable arms 21.

Thus the upper section 2| may be pivoted back around the pivot member 25 so as to open up the box 20, in order to permit access to the inside of the box 20. This position is shown in dotted lines on Fig. l. The pivot bolt 26 may be tightened to hold the sections 2| and 22 together rigidly when the box 20 is closed.

The upper section 2 i is substantially a cylinder, open at its lower end 30 and closed at its upper end 3i except for a central opening 32 (see Fig. 2). More than half of its lower end 30 is relieved at 33 (see Fig. 4). This relieved level 33 cooperates with a corresponding relieved portion 43 in the lower housing 22 to provide a groove 34 through which the plate |5 can pass and also where the air permeable abrasive impeding means may be held. The upper edge 33 of the groove 34, terminates in a shoulder 35 which may provide the upper half of a guide means for the sheets l5 instead of the rail I4, if desired. The groove 34 preferably extends beyond the center of the box 23, so that the blast nozzles may be centrally located.

The lower section 22 is open at its upper end or mouth 43, and closed at its lower end 4| except for a central opening 42.' Its upper end 40 is cutback at 43 (see Fig. 4) to provide the lower edge 43 for the groove 34. The shoulder 45 may cooperate with the shoulder 35 to complete a guide means for the edge of the plate l5, in place of the bar l4. The non-relieved portions 36 and 46 of the two housings 2| and 22 fit snugly together when the box 20 is assembled.

The lower housing 22 also includes a side opening 41 through its walls. Preferably the side opening 41 is angular and is downwardly inclined, and connects with an integral fitting 48. A suction hose 49 attached to the fitting 48 withdraws the spent abrasive and waste material, in conformance with the aforementioned Patent 2,455,514.

Blast nozzles 50, are provided to fit respectively in the central openings 32 and 42 of the housing sections 2| and 22. The nozzles 50, 60 are preferably positioned directly opposite each other, although they may be staggered where the abraded paths are to be out-of-line instead of in-line. The nozzles 50, 60 connect respectively with blast conduits 5|, 5|. Each nozzle 50, 60 is preferably made from or lined with a very hard material such as silicon carbide. From a relatively wide entrance passageway 52, 62, it tapers down to a long narrow outlet orifice 53, 63 terminating in a mouth 54, 64. The purpose of making the orifice 53, 63 long and narrow is to gain a high velocity of impingement of the abrasive and also to keep the abrasive material from spreading too much when it issues from the nozzle 50, 60. When striking the metal sheet IS, the total spread of the abrasive will be the width of the margin |8 being cleaned. For most purposes this will be about inch. The spread may be varied by moving the nozzles 53, 63 up or down in the openings 32, 42. This may be done by unscrewing the set screws 54a and 64a. When the set screws are loose, the nozzles may be moved both vertically 4 and rotationally to adjust for wear and to change the width of the treated area.

For protection of the metal parts, the nozzles 58, 551' are encased in protecting rubber members 55, 65, and the interior portions of the housing sections 2|, 22 adjacent the mouths 30, 40 are equipped with rubber linings 56, 6B. The rubber members 55, 65, and the linings 55, 66 protect the metal parts from the abrasive which strikes the work piece and flies off. If desired, the other exposed portions of the nozzles and housing can be similarly lined. On the abutting portions 36, 46 of the mouths 30, 40 the rubber linings 56, 66 abut where the box 23 is closed, as in the solid line position in Fig. 1, so as to form a seal on this part of the box and prevent any spilling of abrasive between the abutting housing sections 2|, 22.

The groove 34 is enclosed by an air-permeable maze, which extends around the box 20, and is split to provide entry for the plate l5. In the form here shown the maze comprises a pair of annular bristle brushes I3, held in adjustable collars 1|, 8|. The collars 1|, 8| include overhanging flanges '|2, 82 (see Fig. 2) which narrow the maze openings and thereby cause a more intense air current to impinge with the blast current and sweep away the abrasive. Set screws 13, 83 provide for both vertical and horizontal adjustment of the brushes 10, 80. By this arrangement, the brushes may be rotated so that the brushes wear evenly, and may be raised and lowered to compensate for the gradual shortening of the bristles as they wear out and also for the thickness of the sheet |5 being cleaned. Rubber rings 14, 84 may be provided to seal 01f any passage of air between the collars 1|, 8| and the housing sections 2| and 22.

In operation, equipment such as that shown in Patent No. 2,455,514 may be employed to impel an abrasive-filled air stream into the conduits 5| and 6|. One machine of the type there shown will be sufficient for two boxes 20; the four conduits 5| and 6| may all lead oiT one main blast conduit 85. Similarly the same apparatus may provide suction in the conduit '86 to which the two suction conduits 49 for both boxes 20 are joined.

In operation, the sheets |5 are propelled along by the conveyor members l2 and I3, and are guided by the bars I4. They pass into the boxes 20 beneath the nozzles 50, 30, and the margin I8 is abraded. The abrasive is impelled simultaneously through the nozzles 50, 30 in each box 20 and strikes the margin |8 on both sides of the sheet IS. The air current entering through the brushes 1D, 80 impinges with the blast current and sweeps the spent abrasive into the suction conduits 49. 1

No abrasive is spilled because the box 20 is closed, and the suction current carries away all the spent abrasive. With automatic conveying machinery the sheets may be cleaned at a rate of 45 feet per minute, or more, continuously, each sheet being simultaneously cleaned on both sides of both side edges. The high speed of movement is a factor in preventing distortion of the sheets I5. The path l8 may be blasted on only one side, by proper connection of the blast conduits, and again the high speed will prevent distortion.

It will be understood that the invention is not limited to edge-treating apparatus. It may be used to clean any path across a sheet of material. In order to do this, the opening 34 will then extend all the way across the box, and there will be a suction opening 1! on both the upper and lower sections 2! and 22. I

Furthermore, the apparatus may be used on curved edges. It may be used to clean an annular path in a disc or other sheet, by combining it with a different type of conveying machinery, which will turn the sheet instead of impelling it forward.

Also the boxes 2i], here shown positioned vertically, for horizontal cleaning, may be positioned vertically or at an angle, if desired.

We claim:

1-. An apparatus for abrading a marginal surface area adjacent an edge of metal sheets while confining the abrasive and preventing it from flying about, comprising a hollow imperforate cylindrical housing having a slit extending somewhat more than half way across it, the shoulder at the end of said slit acting as a guide for the sheets passing therethrough; a pair of blast nozzles held in the center of said housing, one on each side of said slit; a pair of maze-like airpermeable abrasive-impeding means secured to said housing and filling said slit so that the sheets can be passed into said housing between said pair of means; an opening through said housing adapted to be connected to a low-pressure suction line.

2. The apparatus of claim 1 in which the housing comprises two cylindrical housing members pivotally held adjacent one another so that they can be swung apart, the open mating faces of said housing members having mating relieved portions covering more than half of their circumference to form said slit said shoulder when they is together.

3. The apparatus of claim 1 in which said maze-like means are a pair of brushes mounted in opposition to each other and terminating ad jacent each other, each brush being mounted in a collar which is adjustable on said housing.

4. An apparatus for continuously treating a marginal surface area adjacent an edge of metal sheets while confining the treating material and preventing it from flying about, comprising a main frame; conveying means mounted on said frame; a hollow housing mounted to one side oi said frame and having a transverse slit therethrough; a pair of blast nozzles in said housing generally facing each other on opposite sides of said slit; means to impel treating material through said nozzles; a maze-like impeding means filling the slit, said maze-like means being split so that sheet material propelled along said frame by said conveying means may be passed into said housing therethrough; an opening through the walls of said housing; and suction means connected to said opening for removing spent treating material therefrom.

5. An apparatus for continuously treating a surface strip of sheet material while confining the treating material and preventing it from flying about, comprising a main frame; conveying means mounted on said frame; a hollow housing mounted to one side of said frame and having a generally transverse opening therethrough; a pair of jet means in said housing generally facing each other on opposite sides of said opening; means for impelling treating material through said nozzles; an air-permeable maze-like means surrounding said opening and having a transverse passageway therethrough for receiving sheet material into said housing; guide means for determining the path of said sheet material; a conduit passing into said housing; and suction means con- 6 nected to said conduit for removing spent treat ing material therefrom.

6. An apparatus for continuously cleaning two opposite marginal edges of sheet metal, comprising a main frame; conveying means mounted on said frame; a pair of hollow housings, one mounted to each side of said frame, each hous ing having a transverse slit therethrough; a pair of blast nozzles in each said housing with their mouths facing in opposite sides of said slit; means to impel treating material through said nozzles; a pair of maze-like impeding means surrounding each slit so that sheet material propelled along said frame by said conveying means may be passed into said housing between them; an opening through said housing; and suction means connected to said opening for removing spent treating material therefrom.

7. An apparatus for treating a marginal surface area adjacent an edge of a metal sheet while confining the treating material and preventing it from flying about, comprising a hollow imperforate housing comprising two hollow members pivotally secured together, the mouths of said members being relieved to provide a slit on one side thereof at their juncture and a shoulder adjacent said slit where the relieved portion of the mouth ends so that said shoulders may act as a guide for the sheets passing through the said slit, which forms a transverse opening extending part of the way through the side walls of said housing; a pair of blast nozzles held in said housing, one on each side of said transverse opening with their openings generally opposite each other; an air-pervious inaze-like abrasivedeflecting means filling said transverse opening, said means having a transverse line of separation so that sheet material can be passed into said housing through said line of separation; and a conduit passing through the walls of said.housing and adapted to be connected to a low-pressure suction line.

8. An apparatus for treating a marginal surface area adjacent an edge of a metal sheet while confining the treating material and preventing it from flying about, comprising a hollow imperforate housing having a transverse opening extending part of the way through its side walls; an interior protective layer of rubber lining the inner surface of said housing, the surface of said layer being exposed, said layer extending a substantial distance above and below said transverse opening so as to cover substantially the entire surface of the portion of said housing against which treating material ordinarily strikes after its deflection by the metal sheet being treated; a pair of blast nozzles held in said housing, one on each side of said transverse opening with their openings generally opposite each other; an airpervious maze-like abrasive-deflecting means filling said transverse opening, said means having a transverse line of separation so that sheet material can be passed into said housing through said line of separation; and a conduit passing through the walls of said housing and adapted to be connected to a low pressure suction line.

9. An apparatus for treating a marginal surface area adjacent an edge of a metal sheet while confining the treating material and preventing it from flying about, comprising a hollow imperforate housing having a transverse opening extending part of the way through its side walls; a pair of blast nozzles held in said housing, one on each side of said transverse opening with their openings generally opposite each other v said nozzles being adjustable rotationally and vertically with respect to said housing so as to enable even wear of the nozzles, to correct for wear and to bring them nearer to each other or farther apart and thereby change the width of the impelled treating material where it impinges on the sheet; an air-pervious maze-like abrasivedefiecting means filling said transverse opening, said means having a transverse line of separation so that sheet material can be passed into said housing through said line of separation; and a conduit passing through the walls of said housing and adapted to be connected to a low-pressure suction line.

10. An apparatus for treating a marginal surface area adjacent an edge of a metal sheet while confining the treating material and preventing it from flying about, comprising a hollow imperforate housing having a transverse opening extending part of the Way through its side walls; a pair of blast nozzles held in said housing, one on each side of said transverse opening with their openings generally opposite each other; a pair of air-pervious maze-like abrasive-deflecting brushes filling said transverse opening, said brushes having a transverse line of separation terminating in substantially planar contact with each other so that sheet material can be passed into said housing through said line of separation; and a conduit passing through the walls of said housing and adapted to be connected to a low-pressure suction line.

11. The apparatus of claim 10 in which each of said brushes is mounted in a collar and in which said collars are adjustably secured with respect to said housing, whereby the brushes may be rotated, brought closer together, and moved farther apart to compensate for wear and for the thickness of the sheets being treated.

12. The apparatus of claim 11 in which the collars each include an overhanging rim outside said brush so as to restrict and intensify the entering air current.

13. An apparatus for continuously treating a marginal surface area adjacent an edge of a metal sheet while confining the treating material and preventing it from flying about, comprising a hollow housing having a slit opening through a portion of its walls, so that a metal sheet can be slid along in a straight line with one edge and its adjacent area passing through said slit into and out of said housing; a pair of opposed peripheral air-pervious brushes secured to said housing and enclosing said slit to permit the transverse passage therethrough of said metal sheet and the maze-like passage of air inwardly therethrough while preventing the outward passage therethrough of the treating material; a pair of treating-material-impelling means in said housing facing each other on opposite sides of said slit opening; and suction means for removing spent material from said housing during operation of the device in a current of air.

LEWIS H. BISHOP. JOHN S. FJNN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 727,030 Tilghman May 5, 1903 1,184,894 Taylor May 30, 1916 1,326,913 Cary Jan. 6, 1920 1,419,717 Cary et al June 13, 1922 1,867,856 McCrery July 19, 1932 2,152,352 Holt Mar. 28, 1939 FOREIGN PATENTS Number Country Date 108,256 Australia Aug. 11, 1939 285,883 Great Britain Nov. 15, 1928 

